This is not happening every night.

How's everybody?

For listening practice, I'm determined to watch movies over and over again,
and this time my choice is a film, 'Chloe'.

A mother, as usual, is having coffee in the morning,
and , to her great surprise, she notices a girl wandering around her house.

Not knowing who the girl is, she asks who she is and
it turns out that the stranger was her son, Micheal's girlfriend, and
Micheal and the girl spent the night together in the house.

Annoyed, the mother begins to tell him off, saying
'What? She's in my house and nobody tells me?
Jesus, Micheal. This is not okay."

He doesn't even respond. He hates his mother.
After a pause, she asks, "Are you using protection?"
and the girl says they use condoms.

She stops the conversation, just adding
"This is not happening every night. Understand me?"

Pretty simple conversation, huh?
However, the last sentence is rather puzzling to me.

What did she mean by that - This isn't happening every night.
Here are my guesses.

1. Not every night.
But if it happens every other night, it's okay.
Two days a week? Four days a week? That's fine,
but seven days a week or every night? No way!
It's okay as long as it's not every night, that is, seven nights a week.

2. Not even one single night is acceptable.
Three nights a week? No. Just one night a week? Forget it!
If this ever happens again, you're dead meat! Okay?

Well, from the context, I'd assume what she meant is the second one,
as she looks so stunned and shocked.
From the looks of it, there seems to be no room for compromise.

Do you often use that pattern 'not.. every' when you'd like to put some emphasis on what you're saying, like, "You should not drink every night!"?

Is 'You should not drink every night' almost same as 'You should not drink at all?"

Please help me figure out what the mother meant by that - not.. every night.
I'd appreciate your comment.